Compositions of Diacyl-, Alkenyl-Acyl-, and Alkyl-Acyl Glyceryiphosphoryicholine and -Ethanolamine in Male and Female Rabbit Hearts

Abstract

Detailed analyses of phospholipids were performed using male and female rabbit hearts (body weight, 2.5–3.0 kg). No difference between male and female was detected in the lipid-phosphorus content in 1 g of wet tissues or in the composition of the phospholipids. The amounts of the diacyl-, alkenyl-acyl-, and alkyl-acyl-components in cholinephosphoglyceride (PC) were 57%, 40%, and 3%, respectively. The results were the same in both male and female. The amount of the diacyl type of ethanolaminephospholipid (PE) was higher than that of the alkenyl-acyl type in the male (55%, 43%), but the contents of these two components were the same in the female rabbit (49%). The amounts of the alkyl-acyl types were about 3% in both the male and female. The main difference between the male and female rabbit hearts was in the amount of C_18:1 and C_18:2 :2 acids in PC, i.e., more C_18:1 than C_18:2 was detected in the male, whereas the reverse was the case in the female. The fatty aldehyde compositions of the alkenyl-acyl type PC were a little different from each other. Less C_16:0 and more C_18:0 and C_18:1 aldehyde were observed in the male than in the female, while no difference between male and female was observed in the fatty acid and fatty aldehyde compositions of PE. The fatty acid compositions at the 1- and 2-positions of diacyl- and alkenyl-acyl type PC and PE were analyzed. The fatty acid composition of the diacyl type PC at the 2-position and that of the alkenyl acyl type were similar except that more C_18:1 and less C_20:4 were found in the former in both the male and female rabbits. Different ratios of C_18:1 to C_18:2 between the male and female were also detected in these two fractions. The fatty acid composition of diacyl type PE at the 2-position and that of the alkenyl acyl type were similar except that more C_18:0 was observed in the former than in the latter, and small but significant amounts of C_20:5 and C_22:3-6 were clearly present in the latter, in contrast to the former, in both the male and female. As regards the fatty acid composition of the diacyl type compounds at the 1-position, no difference was observed in PC between the male and female, while more C_16:0 and less C_18:0 was found in PE in the male than in the female.